Vitamin D and calcium, alone or in combination, are often recommended for the prevention of osteoporotic fractures in elderly people. In the study, Adrian Grant of the University of Aberdeen, UK, and colleagues recruited around 5300 people aged 70 years or older who had suffered a fracture in the last ten years from 21 hospitals across the UK.

Participants were randomly assigned to take a daily supplement of vitamin D3, calcium, both, or a placebo and were followed-up for between 24 and 62 months. Overall, 698 participants had a new fracture. The incidence of fractures did not differ between the groups.

The trial did not address whether supplementation should be used for primary prevention or for those who live in a care-home environment. The authors note that clarification of the role of supplementation in these settings awaits the results of other trials.

Grant states: "Our trial indicates that routine supplementation with calcium and vitamin D3, either alone or in combination, is not effective in the prevention of further fractures in people who had a recent low-trauma fracture.

"Policies for secondary prevention should therefore consider other strategies. The main pharmacological intervention is antiresorptive drugs, such as bisphosphonates, which have rarely been assessed in patients who have not been taking calcium of vitamin D.”

In an accompanying Comment Philip Sambrook of the Royal North Shore Hospital, Sydney, Australia, states: "Interpretation of the study is limited by two main factors. First, compliance with medication was only moderate. It declined to 63% after two years and might have been as low as 45% when non-responders to the questionnaire about compliance were included. Second, the study perpetuates the limitations of most previous studies by measuring 25-hydroxyvitamin D in only a small sample.”